Washington (CNN) – Moderate Pennsylvania Republican Rep Jim Gerlach announced on Monday that he will not run for re-election in November presenting House Democrats with a potential opportunity to pick up the seat this fall.

Gerlach, who represents a suburban district outside Philadelphia, released a written statement saying after 6 terms in the House and 12 years in the state legislature, "it is simply time for me to move on to new challenges and to spend more time with my wife and family, who have been extremely supportive and have made significant sacrifices during my tenure in public office."

The CNN 100 takes a look at the top 100 House races, from now until Election Day.

Editor's Note: In the final 100 days before Election Day, CNN has been profiling one race at random each day from among the nation's top 100 House races, which we've dubbed "The CNN 100." Read the full list here. Today's featured district is:

Even though Democrats may have their hands full this year defending dozens of vulnerable House incumbents, they still have high hopes of knocking off several Republican members in districts that President Obama carried in 2008. One such GOP incumbent is Rep. Jim Gerlach, who is no stranger to the Democratic target list.